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(No Model.)

H. A. PITCHER.

LIGHTNING PROTECTOR.

No. 317,848. Patented May l2, 1885.

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UNiTnD STATES PATENT Orricn.

HORAOE A. PITCHER, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR, BY MESNEASSIGNMENTS, TO ROBERT E. VILLIAMS, OF NE'W YORK, N. Y.

LIGHTNING-PROTECTOR.

.SPECIFICATION termingpart of LettersPatent No. 317,848, dated May 12,1885.

Application nieu .my 3, 1884. (No model.)

To all whom, it may concern:

Be it known that I, Hormon A. PITCHER, a citizen of the United States,residing in Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements inLightning-Protectors, of which the following is a specication.

My invention relates to the class of instru- Io ments employed for thepurpose of protecting telegraphic and other electrical instruments frombeing destroyed by the action of currents of abnormal strength which maythrough accident be caused to traverse a circuit in which theinstruments are included. Various instruments have been devised for thepurpose of accomplishing this result, and these have been designed insome instances to out the instruments entirely out of circuit when the2o conductors are traversed by abnormal currents, while in otherinstances they are designed to establish a shunt-circuit around thesame. Still another class serves to establish an earth-connection forthe main conductor 2 5 independently of the circuit connections throughthe instruments. In certain classes of electrical circuits it isessential that the normal connections of the line shall not at any timebe interrupted, because of the liability of 3o an imperfect electricalconnection being made between the contact-points which must then berelied upon to normally complete the circuit. An instance of this isfound in the case of tirealarm telegraph systems,where it is veryessential that the signal-transmitting boxes shall always be in circuit,and that there shall be no possibility of the circuit becominginterrupted by reason of animperfect connection being made at anycontact-points. For this reason an instrument which is organized to cutthe signal-boxes entirely out of circuit or to disconnect them from themain line when the conductors are traversed by abnormal currents isunsuited; and it is desirable, therefore, that an instrument should beemployed which, while capable of affording for the abnormal current apath around the instrument to be protected, will at the same time renderit unnecessary to disconnect those instruments from the line. It isessential, moreover, that 5o the apparatus be constructed so that itwill respond to the abnormal currents with such promptness that theshunt-circuit shall be established before the instruments which are tobe protected can be injured by the current. To this end my inventionconsists, generally, in constructing an electro magnet with two coils,one end of each' coil being connected with the main line, while theremaining ends are connected with the conductor including 6o theinstruments to be protected. Normally, therefore, a current from eitherdirection traverses rst one coil of the electro-magnet, then theinstrument to be protected, and then the second coil of the electromagnet. The cir- 65 cuit-connections, moreover, are such that thecurrents will traverse both coils in the same direction. The instrumentsto be protected are thus included in the circuit of the main linebetween the two coils oi' the electro-mag- 70 net, so that,whether thecurrentbeconsidered as traversing the main line to the instrument fromone direction or the other or whether it be considered as a positivecurrent coming from one direction and a negative current simultaneouslyproceeding from the other direction, it is evident that the current musttraverse at least one coil of the electro-mag netbeforeit reaches theprotected instrument, and the electro-magnet will thus be vitalized 8obefore the current reaches that instrument. Applied to theelectro-magnet is an armaturelever which normally rests against aninsulated back contact-stop. There is also applied to this lever a frontcontact-stop,which is in electrical connection with that terminal of oneof the coils which is connected with the main line. rIhe armature-leveris in like mannerin electrical connection with the correspondingterminal of' the other coil, so that when the 9o lever is drawn towardthe electro-magnet a shunt-circuit will be completed directly acrossfrom the incoming to the outgoing terminal of the main line, thusshunting the coils ofthe electro-magnet and the instruments included inthe circuit therewith. rPhe armature and its lever are so adjusted thatthey will not respond to currents of the strength normally 2 erasesemployed for actuating the alarnntelegraphie, or other apparatus, butthey will readily respond to currents having sufficient strength to doinjury to the instruments included in the circuit, and when they havethus responded and the shunt-circuit has been established a fractionofthe current will traverse the normal circuit through theelectro-magnet, and this, while not of sufficient strength to injure 1othe instrun'1ents,will be suticient to retain the armature in itsforward position, thus keeping the shunt-circuit closed.

In the accompanying drawings, Figure l is a side elevation,and Fig. 2 isa plan view,of an i5 instrument embodying the features of my invention.Fig. 3 is a diagram showing the circuit-connections.

Referring to the drawings, A represents a suitable base,upon which isplaced an electromagnet, B. This electro-magnet is provided with twocoils ofinsulated wire, which for convenience may be considered asconstructed by winding two insulated conductors, C and C, upon the coreZ) at the same time. One terminal,c,of the conductor C is connected withthe binding-post (Z, to which it is designed that the main line L shallbe connected. The opposite terminal, c, ofthe second coil, C2, isconnected in like manner with the binding- 3o post d2, and thisbinding-post is intended to receive theterminal of the main line L. Thesecond terminal, c3, of the rst coil, G, is-conneeted with thebinding-post (Z3, and the second terminal, et, of thesecond coil, C2, iscon- 5 5 neeted with the binding-post d". The respectiveterminals of thelocal conductor Z, in which are included the instrument llI,which is tobe protected, are connected with the bindingposts d and (Zt,respectively. It will be seen, 4o therefore,that the normalcircuit-connections are from the main line L to the binding-post tZ,through the coil C to the binding-post (Z3, thence through the conductorZ, including the instrument llI,to the binding-post CZ", and thus,through the coil Gte the binding-post fZ2,and

to the main line L2. lVhether,therefore,a eurrent be considered aspassing from the main line L to the instrument or from the main line L2to the instrument, or whether it be consid- 5e ered as a positivecurrent from the line L and a negative current fromthe line L2, it willbe understood that it will be impossible for such current to reach theinstrument M until it has traversed one coil of the electro-magnet B.The electro-magnet will thus be vitalized before the current can haveinjured the instrument.

Applied to the electro-magnet B is an armature, E, carried upon a lever,c. This lever 6o is normally held against an insulated backcontact-stop, j", which is carried upon a suitable standard, F. rIhearmature-leveris normally held backward by an adjustable retractilespring, f2, which extends from the lever 6 5 to an adjustable screw, f",extending through the standard or post F. `Suitable nuts, fand f, areapplied to this screw for the purpose of adjusting its position, andthus the tension exerted by the spring upon the armaturelever. Theresting-stop f of the armaturelever is either of insulating material, orelse the post F itsell'is insulated from the remaining parts of theinstrument. Applied to the armature-lever is a front contact-stop, h',and this stop is, for convenience in construction, carried upon ametallic band, z, which surrounds the electro-magnet and holds it inposition upon the base A. A similar band, g', is applied to the otherextremity ofthe electromagnet for the purpose of assisting in holding itin position. rIhe band h2, and thus the point it', are placed inelectrical connection through a conductor, 5, with the binding-post cZ.In like manner the armature-lever c', and thus the contact-point f3,carried at its cX- tremity, are placed in electrical connection througha conductor, G, with a binding-post, at. rIhe conductors 5 and 6, whichserve thus to place the two binding-posts d and d in electricalconnection with each other when the armature-lever is in its forwardposition are of such size and conductivity that the shunt-circuit, whichis established by the forward movement of the lever, will oii'er muchless resistance than the circuit through the coils of the electro-magnetand the conductor Z. The greater portion therefore ot' an abnormalcurrent will traverse this conductor when the electro-magnet has beenvitalized sutliciently to draw its armature into its forward position,and the port-ion ofthe current which will traverse the coils of theelectro-magnet and conductor Z is insul'tlcient to do injury to theinstrument M, although it will be sufiicient to retain thearmature-lever in its forward position.

In the drawings I have shown at M an instrument of the characteremployed in iirealarm telegraphs, the purpose ot" which is to interruptthe main-line connections a predetermined number of times when theinstrument is actuated for the purpose of transmitting an arbitrarysignal to the central station. Various other instruments, eitherelectro-magnets or other circuit-controllers, having delicatecontact-points, may, ifdesired, bcincluded in the conductor Z. It willbe observed that the circuit-connections of this instrument are notchanged when the electro-magnet is vitalized, and that should theshunt-circuit be established through the instrumentality of theelectro-magnet B the circuit-connections of the instrument will beretained, and immediately upon the cessation oi' the abnormal currentthe instrument will be in a condition to operate. If for any reason thearmaturelever f should be retained in its forward position, or shouldthe adjustment of the retractile spring f* be such that it will permitthe armature to be drawn into its forward position under the influenceof a current of normal strength, it will not in any way prevent IOO IIO

IIS

ISO

the operation of the transmitting-instrument M, as will be understood,when it is considered that the electro-magnet B depends for itsinagnetism upon the current which also traverses the conductor Z. If,therefore, the instrument M be actuated so as to interrupt and establishthe circuit-connections through the conductor Z, the electro-magnet Bwill also be magnetized and demagnctized in the corresponding manner, sothat its armature-lever will be actuated in correspondence with theinterruptions of the circuit-connections through the conductor Z. Theconnections between the conductors L and IP will thus be made andinterrupted by 'means of the armature-lever c, in conformity to theinterruptions of the circuitconnections through the conductor Z, and asignal will be transmitted upon the main line identical with that whichis normally transmitted by the action of the instrument M.

I claim as my inventionl. The combination, substantially as hereinbeforeset forth, with an electrical instrument and a conductor including thesame, of an electro-magnet having two magnetizing-coils respectivelyconnected with the terminals of said conductor, an armature-leverapplied to said electro-magnet and connected with the remaining terminalof one of said coils, and a contactstop applied to said armature-leverand connected with the remaining terminal of the other of said coils.

2. The combination, substantially as hereinbefore set forth, with anelectrical instrument and a conductor in which said instrument isincluded, of an electro-magnet having two magnetizing-coils connected inseries with said electrical instrument and respectivelylocated uponopposite sides of the same, and a shuntcircuit across the outerterminals of said coils, which circuit is established by the action ofsaid electro-magnet.

3. The combination, substantially as hereinbefore set forth,with anelectro-magnet having two magnetizing-coils, of an armature andarmature-lever applied to said electro-magnet, an adjustable retractilespring applied to said armature-lever, an insulated back contactstopagainst which said armature is normally held by the action of saidretractile spring, front contact-stop, two binding-posts which arerespectively connected with the outer terminal of one of saidmagnetiZing-coils and the inner terminal of the other of said coils, andalso with said contact-stop and said armaturelever, respectively, andtwo binding posts which are respectively connected with the innerterminal of the first-named magnetizingcoil and with the outer terminalof the second niagnetizing-coil.

4. The combination, substantially as hereinbefore set forth, of anelectro-magnet having two independent magnetiZing-coils, anarmature-lever applied to the same, a front contactstop applied to saidarmature-lever, a metallic band serving to secure said electro-magnet toits base and carrying said contact-stop, and means, substantially suchas described, for placing said armature-lever in contact with said frontcontact-stop.

In testimony whereof I have hereunto sub- -scribed my naine this 2d dayof July, A. D.

HORACE A. PITCHER.

Vitnesses:

DANL. W. EncncoMB, GHARLns A. TERRY.

